Maurice Lévy, chairman and chief executive of Publicis Groupe, said the acquisition would be a valuable addition to the group's digital roster, and said Publicis would accelerate its growth strategy.

Lévy said: "With Rosetta, we aim to enrich our digital knowledge, our capabilities in technology, marketing consulting, and digital strategy, and the creativity we offer to clients and advertisers. This is consistent with our commitment to anticipate and meet their needs in the rapidly-evolving advertising and marketing services landscape."

Rosetta launched in 1998 with 40 people, based in Princeton, but has grown to include offices in New York, Cleveland, San Luis Obispo, Los Angeles and San Jose. It now employs 1,100 people in total.

Kuenne said: "To achieve our long-term business and geographic growth potential, we need the reach and resources of a global group, and we are particularly proud to be joining one of the most advanced digital communications groups in the world."

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